1. Field of the Invention
The present invention relates to isoelectric point markers for isoelectric focusing with fluorescence detection.
2. Related Background Art
Since Picton, H. and Linder, S. E. observed in 1892 that when an electric field is supplied as particles with charges on the surfaces are suspended in an electrolyte solution, the particles migrate toward the opposite poles to the charges of the respective particles, the phenomenon, electrophoresis has been used as means of separation and analysis. After Tiselius has completed his apparatus in 1937, fields of applications have been expanding rapidly heretofore.
Ordinary electrophoresis utilizes differences of net charge states at a certain specific pH, whereas after Vesterberg, 0. and Svensson, H. developed carrier ampholytes as an amphoteric electrolyte in 1966, the isoelectric focusing has been established utilizing a phenomenon that each amphoteric electrolyte has the effective net charge of zero at a certain pH so as to stop migrating.
Here, the value of pH where the effective charge becomes zero is called as an isoelectric point of that substance. In the isoelectric focusing method, a substance stops as concentrated at a position equal to the isoelectric point on a pH gradient formed in a focusing carrier.
Since substances are separated as concentrated in a focusing manner as described , it may provide a separation or analytical method with much higher sensitivity in an electrophoresis.
Further developed recently was a capillary isoelectric focusing in which electrophoresis was effected in a fine tube (capillary) made of a fused silica and having the inner diameter 5 to 100 .mu.m and the length of 30 to 100 cm. Since the capillary isoelectric focusing has a high resolution with a small amount of sample, it has been applied to not only separation and analysis of proteins, but also separation and analysis of inorganic ions, low-molecular weight compounds, and nucleic acids.
There are further attempts to quantify concentrations of separated components in a sample by a detector set at one end of the capillary tube.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.